Combined mold and alignment fixtures



Feb. 17, 1959 c. H. TRIMBLE 2,873,476

COMBINED MOLD AND ALIGNMENT FIXTURES Filed Oct. 19, 1953 2 Sheets-Sheet l INVENTOR ATTORNEY Feb. 17, 1959 c. H. TRIMBLE 2,873,476

COMBINED MOLD AND ALIGNMENT FIXTURES Filed Oct. 19, 1953 2 SheetsSheet 2 INVENTOR Jarles 12712670626 7 BY W ATTCRNEY United States Patent COMBINED MOLD A'ND ALIGNMENT FIXTURES Charles H. Trimble, Winston-Salem, N. 0., assignor to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application October 19, 1953, Serial No. 386,855 2 Claims. (Cl. 18-5) This invention relates to combined mold and alignment fixtures, and more particularly to a plurality of electrical test fixtures having a mold mounted thereon.

It is an object of the present invention to provide a simple and efiicient apparatus for combining testing and molding operations performed on electrical components. In accordance with one embodiment of the invention, a plurality of pin chuck-holding assemblies are laterallyspaced and mounted on a base. Each of the assemblies aligns and holds a plurality of pins and is adapted to electrically connect the pins and electrical components attached thereto to an external electrical test circuit. A mold having a plurality of laterally-spaced cavities is detachably mounted on the base for surrounding the electrical comopnents attached to the pins so that a plastic material can be poured into the cavities and envelop the electrical components.

A complete understanding of the invention may be obtained from the following detailed description when taken in conjunction with the accompanying drawings wherein; p

Fig. 1 showsa plan view of the combined mold and alignment fixtures;

Fig. 2 shows a front-elcvational view of the fixtures of Fig. 1;

Fig. 3 shows a cross sectional view of a fixture taken along the line 33 of Fig. 2;

Fig. 4 shows an enlarged view of the pin chuck-holding assembly of Fig. 3;

Fig. 5 shows a cross section of the pin chuck-holding assembly taken along the line 5-5 of Fig. 3;

Fig. 6 shows a guide plate;

Fig. 7 shows a pin chuck; and

Fig. 8 shows a perspective view of a finished article formed by. one of the mold and alignment fixtures of the invention. s

Referring now in detail to the drawings, wherein the same reference characters are employed to designate the same parts throughout the several views, the combined mold and alignment fixture is mounted on a base 10 which has a plurality of laterally-spaced circular apertures passing therethrough, one of the apertures being designated by the numeral 11 in Figs. 3 and 4. A plurality of flat guide plates 12 are secured to the base 10 by thumbscrews 14 which pass through apertures 16 (Fig. 6) of the plates 12 and are threaded into the base 10. The plates 12 have circular apertures 17 in the center thereof, which apertures 17 are smaller than and concentric with the apertures 11 of the base 10. The plates 12 also have laterally opposed projections 18 ex tending therefrom.

Secured to the plates 12 by means not shown in the drawings are a plurality of insulating disks 19, each having a multiplicity of radially disposed apertures 29 formed therein. The insulating disks 19 may be made of a dielectric material, such as phenol fiber or similar materials.

face of member 21.

2,873,476 Patented Feb. 17, 1959 To each plate 12 is secured a cup-like member 21 of insulating material, such as phenol fiber, which has a flange through which the screws 22 pass to secure the member 21 to the plate 12. Mounted within the cuplike member 21 is a solid cylindrical member '24 which is also of insulating material such as phenol fiber and which has a cylindrical surface 26 and a plurality of grooves 27 extending axially along a portion of the cylindrical surface thereof. Each cylindrical member 24 is held in position within the cup-like member 21 by a screw 28.

In the lower part of the members 21, as seen in Figs. 3 and 4, apertures 29 are formed. Adjacent each aperture 29 a slot as indicated at 30 is cut, each slot 30 be ing tapered as at 31 and merging into the aperture 29. Also in the lower part of member 21, screws 32 are threaded in holes tapped above each slot 30 in member 21 and adjacent the cylindrical surface 26 of the member 24.

It is clear from the description above that directly beneath each aperture 20 in the disk 19 is a first passageway defined by the groove 27 of member 24 and the inside surface of member 21. Directly beneath this first passageway is a second passageway defined by the surface 26 of the member24 and the inside surface of member 21, and finally, directly beneath this second passageway the aperture 29 of member 21 is located.

Into the first passageway defined by the groove 27 of member 24 and the inside surface of member 21 is placed the upper portion 34 of an electrically-conductive metal pin chuck 36 of Fig. 7. The lower portion 37 of the pin chuck 36 is placed in the second passageway defined by surface 26 of member 24 and the inside sur- An electrically-conductive wire 38 of copper, for example, is soldered to the lower portion 37 of the pin chuck 36. Upon placing the pin chuck in the passageways as described above, the wire 38 is brought through the apertures 29 of the member 21, through the slot 30 close to the tapered portion 31, and is secured by soldering to the exposed end of the screw 32 after the screw 32 has been turned in to make good electrical contact with the lower, portion 37 of the pin chuck 36 by tightening the portion 37 against the surface 26.

Mounted on the disks 19 are a pair of walls 39 of similar construction having notches 40 formed therein.

When the walls 39 are brought together as shown in bolts 44 which are pivotally mounted on the walls 39 at 46. Projections 47 and 48 are secured to base 10 and are provided to guide the assembling of the walls 39 by projecting thru apertures 49 and 50, respectively, of the walls 39.

Directly adjacent the notches 40 on each wall 39 a cam 51 is pivotally secured by a bolt 52. A head 54 of the bolt 52 is recessed in a counterbore 56 of a nut 57 which is cast as an integral part with thecam 51. An arcuate slot 58 is formed in the cam 51 to cooperate with the lower surface of the projections 18 so that when a the nut 57 is turned in a clockwise direction (as viewed 3 crate temperatures and atmospheric pressure. Examples of such resins are epoxy resins, unsaturated polyester resins, styrene-polyester copblymer resins, and the like. The amplifier is provided with a plurality of electrical connectingpins 61. V I

A plurality "of the pins 61 are first placed in the upper portions 34 of the pin chucks 36. In the present embodiment of the invention there are nine pin chucks 36 in each assembly to conform to the nine apertures 20 shown in each disk 19 in Fig. 1 and in each amplifier of Fig. 8.

The pins 61 are of course first placed through the apertures 20 of the disk 19. In this position the pins 61 are in the upper portion 34 of the pin chucks 36 which are positioned directly below the apertures 20 of the disk '19 in the passageway defined by the grooves 27 of the cylindrical member 24 and the inside surface of the member 21. The pins 61 are therefore electrically connected to the screws 32 to which are soldered the copper wires 38.

The electrical components that comprise the package amplifier are then soldered to the upper portions of the pins61.

When each pin chuck holding assembly has the soldered package amplifier units positioned as described above, the base is then placed in a testing fixture (not shown) which connects the screws 32 and hence the package amplifiers to a testing device to assure that each amplifier is correctly connected. If one of the amplifiers should fail the test, other amplifier components are soldered to the pins 61.

When all the units have satisfactorily passed the various electrical tests, the molding cavities are then formed around the units by placing the walls 39 into the position shown in the drawings. The wing nuts 42 are tightened to firmly hold the walls 39 together and the cams 51 are rotated clockwise to firmly seat the bottom of the walls 39 against the disks 19 I When thus positioned, the thermosetting plastic material is then poured into the molding cavities defined by the notches 40. The molding unit and base are then placed in an oven where the thermosetting material is cured.

After curing, the unit is then removed from the oven and the walls 39 are removed. The base unit is then placed in the testing fixture where each amplifier is again tested.

The testing fixture may be any suitable type, the important feature being that .each corresponding screw 32 of each pin chuck assembly be connected by suitable switching means to the same electrical test device. The connectors of the testing device that electrically connect the screws 32 may be of the spring clip type so that thepin chuck-holding assemblies may be easily placed in and detached from the tester with the screws 32 making good electrical contact with the spring clips.

It s to b u d' t qd t a hsab x de sr si 51 semblies are simply illustrative of the principles of the invention, and many other: modifications may be made without departing from the invention.

What is claimed is:

l. A fixture for pretesting and encausulating electrical components including conducting wire leads, which comprises an insulated support having recesses therein, the support forming a mold bottom, a conducting. chuck in each of said recesses for slidably receiving. said leads, a contact connected to each of said conducting chucks and disposed on said support whereby said contacts may be associated with an externalv test circuit to permit pretesting of the connections and characteristics of the said components before they are encapsulated, and a hollow mold including walls detachably secured to the mold bottom formed by the support to surround said components butleave bared the terminal portions of the wire leads and receive an encapsulating plastic in a liquid state, said support and walls being removable from the encapsulated components after said plastic material has solidified.

2. A fixture for pretesting and encapsulating electrical components and substantially parallel, rigid conducting wire leads secured to said components, which comprises a horizontal support having recesses therein, the support forming a mold bottom, a conducting chuck in each of said recesses for slidably receiving said leads in a vertical position above said support and thereby to support said components, a contact connected to each of said conducting chucks and disposed on said support whereby said contacts may be associated with an an external test circuit to permit pretesting of the connections and characteristics of the said component before they are encapsulated, and a hollow mold including walls dctachably secured to the mold bottom formed by the support so as to completely surround said components but leave bared the terminal portions of the wire leads and to receive an encapsulating plastic ina liquid state, said support and walls being removable from the encapsulated components after said plastic material has solidified. 1

References Cited in the file of this patent UNITED STATES PATENTS 1,796,421 Apple Mar. 17, 1931 1,847,888 Nickle Mar. 1, 1932 2,027,165 Grubman Ian. 7, 1936 2,559,141 Williams -s. July 3, 1951 2,586,609 Burke Feb. 19, 1952 2,729,850 Dewees JanrlO, 1956 2,738,466 Niederman Mar. 13, 1 956 2,795,664 Conrad June 11, 1957 2,827,618 

